This is something I have been thinking about more since I lost my husband last year. I'm perfectly fit and not frail, but I could still be taken ill or have an accident.
I don't have pets, but I still worry about myself. My daughters, who don't live locally, tell me I should keep my phone handy, especially at night, and I suppose they're right.
Another thing that has occurred to me is that when I lock up at night, I leave the key in the lock. I have a spare key hidden outside, and several friends who know where it is, but they wouldn't be able to get in while there's a key on the other side of the door. I ought to remove the inner key when I lock the door.
If I need to go into the loft via the pull-down ladder, or do anything in the garden that requires a step ladder, I try to wait until there's someone else with me, or ask a friend to come round, just in case I fall.
I suppose all this is the price we pay for our independence.